Switching device



June 29 1926.

B. O. AUSTIN SWITCHING DEVICE Original Filed y 12, 1919 WITNESS-ES: /6 MINVENTOR fiddCU/f) O/Iuofln AT.TORNEY Patented June 29, 1926.

UNITED STATES PATENT OFFICE.

' BASCUM O. AUSTIN, OF EAST PITTSBURGH, PENNSYLVANIA ASSIGNOR'TOWESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OFPENNSYL- VANIA.

SWITCHING DEVICE.

Application filed May 12, 1919, Serial No. 296,616. Renewed January 14,1926.

My invention relates to control apparatus of the Well-known unit-switchtype and it has for its object to provide an improved actuatingmechanism whereby a smooth, rolling action may be effected during theclosure and opening of the switch contact members.

More specifically stated, it is the ob ect of my invention to provide aswitch of the above-indicated character wherein power means and a springbear upon different parts of the movable contact member, and alostmotion connection between the movable member and its support isarranged to effect opposing action of the power means and the spring..o.nly during a predetermined portion of the switchim'ovement.

. My invention may best be understood by reference to the accompanyingdrawing, wherein the single figure is a view, in side elevation, of theessential parts of a switching device constructed in accordance with theinvention.

Referring to thedrawing, the unit-switch structure here shown comprises,in general, a stationary contact member 1; a co-opcrating movablecontact member 2; and an actuating mechanism 3 and power-operated means4 therefor.

The stationary contact member 1 is of a familiar type comprising a bentcontact tip 5 which is secured to a bracket or standard 6 that issuitably attached to the top frame member or cover 7 for the entireswitch roup.

The movable contact member 2 comprises a similar contact tip 8 that ismounted upon one end of a'switch arm 9, the other end of which isprovided with a pin-and-slot or.

other lost-motion connection 10 with a stationary support or bracket 11,which is also secured to the top frame member 7. A coil sprin 12 issecured between the switch arm 9 an the frame 7 bearing upon the switcharm near the lost-motion connection 10. The power means 4 for closingthe switch is pivotally secured to the switch arm 9 near the contact tip8, whereby the switch arm is provided with two pivotal connections-.13,just mentioned, and 14, forming an element of the lost-motion connection10. A braided shunt or conductor 15 serves to divert current from thespring 12 and the lost-motion a familiar electrically-controlled,fluid-actuated device. The usual insulator 20 is interposed between thepivotal point 13 and the air-cylinder 21, within which a movable piston(not shown) is adapted to travel, as will be understood by those skilledin the art. A magnet valve 22 of well-known construction is employed forthe purpose of controlling the supply of fluid pressure to the cylinder21 and, if desired, an electrical interlock 23, of the familiar typethat is employed for auxiliary control circuits, may be attached to themovable piston rod in the usual manner. Since, as stated above, theparticular type of power mechanism that is employed is immaterial to mypresent invention, I do not deem it necessary to further describetheillustrated mechanism.

Assuming the parts of the switching device to occupy the illustratednormal positions, the closing operation thereof may be set forth asfollows: Upon the initial upward application of force to the pivotalpoint 13, the switch arm 9 rotates around the pivotal point 14 until aninitial contact of relatively small area is made between the contacttips 5 and 8. Up to this point, the

top portion of the slot in the lost-motion connection 10 is held inengagement and bears upon the pivot member 14 by reason of the biasingeffect of the spring member 12 upon the switch arm 9. 'l/Vhen theinitial contact has been made between contact tips 5 and 8, the contacttip 8 acts as a temporary fulcrum, upon continued a plication of forceto the pivotal point 13, an the right hand end of the switch arm 9 isactuated upwardly until the bottom portion of the lostmotion connection10 engages the pivot member 14. In this way. a gradual rolling action ofthe contact tip 8 over the surface of the stationary contact tip 5occurs until complete electrical contact has been estab lished betweenthe two contact tips.

It will be understood that the opening movements of the switch are theexact reverse of those described, the initial propelling force beingsupplied by the customary coil spring (not shown) that is located withinthe air cylinder 21.

Although I have described the operation of the switch as providing asmooth, rolling contact of the tips into the desired'final position, lldesire it to be understood that, by slightly modifying the proportion ofparts, any desired degree of sliding or Wiping action may be substitutedfor the complete rolling action that l have set forth. Consequently, Ido not wish to be restricted to the specific structural details orarrangement of parts herein set forth, as various modifications thereofmay be made without departing from the spirit and scope of my inventionI desire, therefore, that only such limitations shall be imposed as areindicated in the appended claims.

I claim as my invention:

1. A switching device comprising co-operating stationary and movablecontact members, power means attached to said movable member at acertain point, a spring acting at another point in opposition to saidpower means, and a lost-motion connection for said movable memberincluding a stationary member located to one side of both the powermeans and the spring, said power means and said spring acting alongsubstantially parallel paths.

2. A. sw tching device comprising co-opcrating stationary and movablecontact members, a support for the movable memacting upon the movablemember near said eena-ca tionary and movable contact members, a

support, a lost-motion connection, comprising a pin and slot betweensaid movable contact member and said support, energystoring means actingon said movable member near one end thereof and power means acting atanother point on said movable member in opposition to saidenergy-storing means, said power means and said energy-storing meansacting along substantially parallel paths.

5. A switching-device comprising stationary and movable contact members,.a support, a lost-motion connection, comprising a pin and slot betweensaid movable contact member and said support, energy-storing meansacting on said movable member near one end thereof and power meansacting atanother point on said movable member in opposition to saidenergy-storing means, said power means and said energy-storing meansacting along substantially parallel paths, and said slot extending in aparallel direction to said paths;

In testimony whereof, I have hereunto subscribed my name this 30th vdayof April 1919.

BASCUM o. AUSTIN.

